struct group_info init_groups = { .usage = ATOMIC_INIT(2) };

struct group_info *groups_alloc(int gidsetsize){

struct group_info *group_info;

int nblocks;

int i;



nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;


nblocks = nblocks ? : 1;

group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);

if (!group_info)

return NULL;

group_info->ngroups = gidsetsize;

group_info->nblocks = nblocks;

atomic_set(&group_info->usage, 1);



if (gidsetsize <= NGROUPS_SMALL)

group_info->blocks[0] = group_info->small_block;

else {

for (i = 0; i < nblocks; i++) {

gid_t *b;

b = (void *)__get_free_page(GFP_USER);

if (!b)

goto out_undo_partial_alloc;

group_info->blocks = b;

}

}